Thrunite TC20 V2 Review – for Anyone and Everyone


The Boring Stuff

Thrunite sent me this light in exchange for an honest review. Here is the official product page on their website, but it’s also available on Amazon at a lower price. Below are the specs from the official product page.

What comes in the box?

TC20 comes in one of Thrunite’s excellent cardboard boxes. It’s a thick, two-piece box with some basic printing to let you know what’s inside. Inside you find the light nestled in a nice foam insert to keep it protected. I’m always impressed with Thrunite’s packaging because it feels high quality, but in a way that isn’t wasteful. The following items are included in the box:

  • The light itself
  • A battery (installed in the light)
  • A lanyard
  • Spare O-Rings
  • Spare port covers
  • Spare button insert
  • USB A-to-C charging cable (19″)
  • A belt holster

Design & Construction

TC20 V2 has an attractive design that’s largely carried over from the original. It’s mostly cylindrical with a little flare out toward the head with some cooling fins. I quite like how it looks.

Build quality is great. It feels very solid in the hand with no sharp edges. The anodizing is very dark and a bit glossy. The only qualm I have is with the tail threads. They unanodized and feel rough, so I recommend using the head for cell swaps. It’s worth noting that there’s no anti-roll feature.

Size & Measurements

From left to right:
Noctigon KR1
Contoy M21D
Thrunite TC20 V2
Fireflies E07x Pro
Convoy S12

MeasurementMeasured (mm)
Bezel Diameter42.0
Maximum Head Diameter42.0
Switch Diameter8.0
Switch Proudness1.0
Lens Diameter37.9
Lens Thickness2.0
Reflector Hole Diameter11.8
Reflector Diameter35.1
Reflector Height18.1
MCPCB Size~22.4×22.4 (square)
Body Tube Diameter (internal) 27.1
Body Tube Diameter (maximum)32.5
Body Tube Diameter (mode)32.5
Body Tube Length72.1
Tailcap Diameter33.5
Tailcap Length16.0
Driver Diameter~29
USB Port Width12.0
USB Port Depth2.8
USB Port Height8.0
Included Battery Length69.9
Included Battery Diameter26.7

Weight with included battery: 242g

User Interface

This is an excellent, simple user interface.

The actions are # of presses followed by a hold (H) or a release (C). So, “1C” is one click and release. “2H” is two clicks but you hold down the last one.

Off1COn (mode memory)
Off1HFirefly (not memorized)
On/Off2CTurbo (not memorized)
On1HCycle Mode (Low-Med-High)
Normal UI

This is the kind of UI that doesn’t have any weird tricks or hidden settings menu or anything. I can hand this light to my neighbor and explain how to use it very quickly and know that they won’t have any trouble. I do have a couple things to note though.

It responds instantly to a button press. For example, when using the 2C from on shortcut to go to Turbo, the first click turns the light off for the split second between it and the second click. It’s a little disorienting coming from other lights that wait a moment before responding to clicks, but it makes it feel SUPER responsive.

The only things I don’t like about this UI are 2C from Turbo, and the way mode cycling works. 2C from Turbo goes to strobe, but it should go back to the memorized mode. Strobe should be accessed via 3C from anywhere. When cycling modes, if you stop on medium for more than a second or two, when you 1H again to go to High it will actually jump down to low. I believe the intent of this is to make it easy to go down a level, but in reality it just causes brief confusion.

Modes, Brightness, Throw, & Tint

Disclaimer: Lumen measurements were taken on a Texas Ace 3.5″ Lumen Tube. A candela measurement was taken at 10 meters with an Opple Light Master III on the highest brightness, and other candela figures were calculated relative to that. CCT & DUV data was taken for each mode from a few feet away at the center of the hotspot with the Opple Light Master and Waveform DUV Calculator. Runtime tests were performed with the Ceilingbounce app on my smartphone. All of these tests were performed with a fully charged included battery unless otherwise specified. I cannot measure moonlight directly, so moonlight readings are calculated based on the brightness relative to the next-lowest mode. None of this is professional equipment, so take all of these measurements with a grain of salt.

Level Lumens (@ Turn-On)Candela (@ Turn-On)Throw (meters)CCTDUV
CCT = Color Temperature | DUV = Tint | Positive DUV is more green, negative DUV is more magenta

Mode Spacing: is good. There aren’t any oddly large or small jumps.

How does it compare to the official specs? I measured Turbo at ~200lm less than the official spec, but I got the NW version so it should be slightly dimmer. That’s within my lumen tube’s margin of error too, for what it’s worth. But, Thrunite claims their lumen rating complies with the ANSI FL1 standard, and I measured significantly lower (~3300lm) at 30 seconds where you’re supposed to measure for ANSI FL1. I measured candela a fair bit higher at turn-on than the official 22,400cd spec, just like the last two Thrunite products I reviewed, but 22,400cd is just about right for 30 seconds after turn-on. Perhaps Thrunite is measuring lumens at turn on but measuring candela at 30 seconds?


Performance: Turbo always steps down right at 3 minutes regardless of temperature, but after that stepdown the light is thermally regulated. Aside from thermal-related stepdowns, output is pretty flat.

LVP: is present and works well. Every time the light shut off in my testing it was the driver that shut it off, not the battery’s protection circuit. Notably, the low voltage cutoff is very harsh. I would have liked to see a hard drop to low, then moonlight, to extend battery life and provide some warning. The switch will breathes red to warn you, but you might not notice that if you’re walking around at night or if you’re ceilingbouncing to illuminate a room. Once LVP shuts the light off, you must loosen & re-tighten the head if you want to re-activate the light.

Note: There’s always a slight but distinct drop in output right after Turbo activation. You can see it in the Thermal Stepdown graph. Sometimes its almost immediate, sometimes it takes several seconds. I don’t know why this happens or why the timing is inconsistent. It’s not a problem, but I noticed it, it’s weird, and I wanted to mention it.

Driver & Regulation

TC20 V2 uses a 6 volt boost driver. It takes the ~3-4.2V of the battery and boosts it up to the ~6V needed by the XHP70.2 LED. Boost drivers are more efficient than the FET or Linear drivers often found in less expensive lights, and that translates to longer runtimes and/or higher sustained output. They also tend to be fairly well regulated.

Regulation is average. It’s not as good as I had hoped for from a boost driver, but it’s not bad either. Higher modes are affected by cell voltage and lower modes are less affected.

Note: All regulation measurements are taken at turn-on so they do not reflect any thermal or low voltage stepdowns that may occur. A value of 0 indicates low voltage shutoff immediately upon activation.

Thermal regulation: Is present and works well enough. The light does get a little too hot to hold during extended use on Turbo or High modes, but not so hot that it’s concerning. I did a cooled Turbo runtime test and it seems that there’s always a timed stepdown at 3 minutes to High mode, but after that it’s thermally regulated.

Parasitic Drain: 92 microamps. That should take over six years to drain the battery.

PWM: No PWM is visible to my eye. I did some testing on each mode with an Opple Light Master III and found some form of flickering or noise on all modes, but none of it looks quite like PWM. Below are those results if you’re interested, starting with Firefly and going up to Turbo.

Emitter & Beam

TC20 V2 uses a Cree XHP70.2 LED in a relatively shallow orange peel reflector. The bezel is not glued down and everything forward of the LED can be removed fairly easily. Notably, Thrunite is using a very large and non-standard square MCPCB. For TC20 V3, it would be nice to also have a Getian FC40 or FC60 LED option for less tint shift and better color.

The beam is bright and floody, but there’s a lot of tint shift. This is to be expected from an XHP70.2 paired with a reflector. The hotspot is a little bit warm, the corona is yellow-green, and the spill is cool. It’s not the greatest beam for hunting white walls, but it’s perfectly fine during normal use.

TC20 V2 NW

In the beamshots above, the trees where I’m aiming the hotspot are 175M away. In the beamshots below, the park bench where I’m aiming the hotspot is 42M away.

TC20 V2 NW


TC20 has an electronic side switch. The boot appears to be plastic and it’s a different color than the body so it stands out. Right in the center is an indicator LED that shows charge status. More on that in the batteries & charging section.

I can click the switch with either the tip of my thumb or the first knuckle. The switch doesn’t travel much, but it’s tactile enough and very clicky. You have to be fairly deliberate about clicking it so I don’t think it would come on by accident, but if you’re storing it in a bag or in the belt holster, I recommend loosening the head a bit to mechanically lock it out.

Charging StateIndicator LED StateMeaning
Plugged InConstant RedCharging
Plugged InConstant BlueFully Charged
UnpluggedConstant BlueGood Charge Level
UnpluggedConstant RedLow Battery
UnpluggedBreathing RedCritically Low Battery
Switch LED Meaning Chart

Carry & Ergonomics

Ergonomically, TC20 V2 is great. It fits in the hand well without being too big or too small. My thumb lands right on the switch and the milling on the body tube provides plenty of grip without being too aggressive.

Thrunite includes two carry methods in the box: a lanyard and a belt holster. The lanyard is fairly nice, but the belt holster feels a little flimsy to me. It seems well manufactured, but the materials chosen are too floppy for my liking. The loop on the back doesn’t detach at all so you need to un-thread your belt to attach it. There’s a D-ring as well for some reason, and the closure is velcro. Ultimately its a freebie and it’s fine.

I wish TC20 V2 had a strong magnet in the tailcap. That would be a compelling upgrade for TC20 V3.

Batteries & Charging

A 5000mah protected flat top 26650 cell is included and it doesn’t rattle inside the light at all. I measured 5470mah and 74mΩ IR on my SkyRC MC3000 charger. There are very stiff, dual springs in the tailcap and a brass button on the driver for contact. There is low voltage protection built into the light so you can safely use an unprotected 26650 should you so desire. I also tested with unprotected flat top 21700 and 18650 cells and both fit just fine, but the 18650 rattled a bit side to side. Make sure to use a cell with a continuous discharge rating of at least 8 amps just to be safe.

Charging is facilitated by a USB-C port on the head of the light, roughly at 7 oclock if the button were at 12 oclock. There’s a rubber flap covering the port and two replacements are included in the box. It’s the same port used on Catapult V6, and it’s not my favorite. It’s hard to get all the way seated.

Charging stops at 4.17V and took just over 3 hours. While charging, High, Turbo, and Strobe modes are all disabled. USB A-to-C cables work just fine, but C-to-C cables generally don’t. I tried charging from a 18W PD-rated phone charger, a 5V 3A rated power brick, and an LT1-Mini. None worked. I was able to charge TC20 from a Convoy M21D, but M21D is not up to spec itself so I think that was an exception, not the rule. Don’t count on being able to charge this light from a C-to-C cable.


Here are some lights in the same class and how they compare.

Wowtac A5: A cheaper and less fancy version of TC20 V2 from Thrunite’s budget brand: Wowtac. If TC20 is too pricey, this is the best alternative.

Sofirn SP33S: Very similar overall, same LED, same battery, same switch location, same charging solution, powerbank function, fancier UI, less expensive, only available from China at the time of writing.

Convoy M3-C: Same battery size & charging solution, larger head, more LED options, different UI that’s better/worse in different ways, also available with a 26800 battery

Emisar D4SV2: A TC20 V2 alternative for enthusiasts: four LED’s instead of one, tons of LED options, 26650 or 26800 battery, magnetic tailcap, the fanciest UI available, RGB aux LED’s, backlit button, various driver options (including a dual-channel for flood/throw switching or tint ramping).

This section is not comprehensive. If I didn’t include a particular light here, it doesn’t mean it’s bad or doesn’t deserve to be here. I simply cannot list every possible competitor.


Thrunite has put together light that I recommend to just about anyone and everyone because it’s got a great general purpose beam, high build quality, and ease of use. There’s nothing about it that gives me pause when recommending it and there are almost no other lights I can say that about. Well done, Thrunite!

Thanks to Thrunite for sending me this light for review!

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